grid-tied

Solar-plus-battery systems that combine photovoltaic panels and lithium-ion batteries are helping a number of commercial electricity customers cut their power bills, but any widespread spillover to the residential side of the market looks to be some time away.
Two solar installers, SolarCity, and SunPower, are offering the systems to residential customers, yet the numbers in the pilot programs are very modest.

Maine's largest electric utility is seeking permission from state regulators to impose a new “standby” rate that would add roughly $13 to the monthly bill of a residential customer with a grid-tied renewable energy system.
The plan would tack on $24.83 a month to the Central Maine Power power bill for a net-metered residential customer vs. the flat $12 charge for a customer without renewables, CMP said. The proposal is part of a rate case before the Maine Public Utilities Commission.